Ratings agency Standard & Poor may upgrade its outlook for Irish packaging giant Ardagh when it floats part of its business early next year.

Although the total value of the initial public offer IPO will only be around 5pc of Ardagh's market capitalisation, which equates to around €250m, it is seen by the markets as an important step towards reducing debt.

In a recent note on the company, which is headed by low-profile businessman Paul Coulson, the ratings agency said: "Upside to the ratings could occur on evidence of sustainably reduced leverage and a commitment from management to a less aggressive financial policy."

An example of this would be "through its proposed minority IPO which Ardagh has indicated could happen in the coming months". To date, "no meaningful IPO proceeds" have been factored into S&P's numbers, it said.

Coulson has used debt markets to grow Ardagh into a leader in the glass and packaging sector.

In June, it paid $3.4bn (€3.2bn) to buy the beverage-cans business from US company Ball Corporation and Britain's Rexam, paving the way for a major expansion into this sector.

Coulson has been mulling plans for a flotation for several years. Plans to offer shares in Ardagh's Oressa metals division in the US were shelved in late 2015 due to volatile market conditions.